Organic-inorganic hybrid materials

ABSTRACT

The present invention relates to mixtures containing organic polymers, inorganic particles and inorganic-organic binders to organic-inorganic hybrid materials which can be produced from these mixtures and to the use of these hybrid materials.

BACKGROUND OF THE INVENTION

The present invention relates to mixtures for the production oforganic-inorganic hybrid materials and to the use thereof.

By synthesising organic-inorganic hybrid materials, attempts are made tocombine properties which are typical of inorganic and organic substancesin one material. Thus, as is known, glass and ceramics are characterisedby their hardness and brittleness, whereas organic polymers are flexiblebut at the same time are also considerably softer than theaforementioned substances. Meanwhile, very many organic-inorganic hybridmaterials have become known which are considerably harder than organicpolymers are but which nevertheless do not exhibit the brittleness ofpurely inorganic materials.

Hybrid materials are classified into different types depending on thetype of interaction between the inorganic and the organic component. Areview on this topic is given in J. Mater. Chem. 6 (1996) 511.

One class of hybrid materials is obtained by the reaction of ahomogeneous mixture of an organic polymer with metal alkoxides, e.g.Si(OEt)₄ or CH₃-Si(OEt)₃, with water. After hydrolysis and condensationof the alkoxides, an inorganic network is obtained which is penetratedby the organic polymer (“interpenetrating network”). There is nocovalent chemical bonding of the polymer to the inorganic phase.Examples of hybrid materials such as these are given in U.S. Pat. No.5,346,939 and WO 93/01226.

According to Poly. Mater. Sci. Eng. 74 (1996) 65, the compatibility ofthe inorganic phase with strongly polar polymers such as polyamides,polyimides, polyamide-imides or polycarbonates is particularly good.With polymers which are less polar, however, e.g. polyvinyl chlorides orpolymethyl methacrylates, which are extraordinarily important inindustry, phase separation often occurs, i.e. heterogeneous, turbidmaterials are formed. The addition of polyoxazolines has been proposedin order to improve the compatibility in systems such as these.

Another class of materials is produced similarly, but contains reactivegroups, e.g. Si(OEt)₃ groups, in the organic polymer which is used,which reactive groups effect covalent chemical bonding to the inorganicnetwork. Examples thereof are given in ACS Symp. Ser. 585 (1995)125,Adv. Mater. 6 (1994) 372 and in Mater. Lett. 13 (1992) 261.

“Polymeric composites” which consist of an organic polymer and of aninorganic, glassy polymer are described in WO 93/01226. It is stated tobe a characteristic of these materials that the organic polymer cannotbe extracted and that no glass transition point or melting point isobserved.

Mixtures consisting of unreactive, thermoplastic polymers with liquidorganometallic compounds are known from U.S. Pat. No. 5,346,939. In thepresence of water, composite materials are obtained therefrom in whichthere is no mixing at a molecular level, but in which the organic andinorganic phases are separate. Composite materials such as these areturbid, and are therefore unsuitable for applications for which highlytransparent materials are required, for example covering lacquers.

SUMMARY OF THE INVENTION

The present invention therefore relates to mixtures consisting of:

A) at least one organic polymer,

B) inorganic particles,

C) at least one inorganic-organic binder,

D) solvent.

DETAILED DESCRIPTION OF THE INVENTION

Organic polymers A) in the sense of the invention may be polymers whichare reactive or unreactive towards constituents B) and C).

Unreactive organic polymers do not form stable covalent bonds with theinorganic particles or with the inorganic-organic binder. The formationof Si—O—C bonds by the reaction of OH groups of the polymer with alkoxygroups, for example those of the organic-inorganic binder, is not seenin the sense of the present invention as the formation of a stablecovalent bond, since a Si—O—C bond can be cleaved again with water undermild conditions. The “bonding” of the organic polymer to the inorganiccomponents B) and C) in the latter case is essentially due to weakinteractions. e.g. hydrogen bonds.

Reactive organic polymers in the sense of the invention contain groupswhich form stable covalent bonds, essentially Si—O—Si bonds or Si—O—Albonds also, with the inorganic constituents B) and C). Organic polymerscomprising corresponding reactive groups can be produced by(co-)polymerisation, as described in ACS Symp. Ser. 585 (1995) 125, Adv.Mater. 6 (1994) 372 and Mater. Lett. 13 (1992) 261, or by thefunctionalisation of an unreactive polymer. Substances which aresuitable for this purpose exhibit a high level of reactivity towards theorganic polymer and at the same time can also readily be bonded to theinorganic matrix. Examples include bifunctional organosilanes, which arealready widely used as “coupling agents”, e.g. for the embedding ofglass fibres in polymers. In particular, the following organosilanes canbe cited as examples, wherein R=alkyl or aryl, preferably methyl orethyl:

a) H₂N—(CH₂)₃Si(OR)₃

b) H₂N—(CH₂)₂—HN—(CH₂)₃Si(OR)₃

c) H₂N—(CH₂)₂—HN—(CH₂)₃Si(OR)₂(CH₃)

d) C₆H₅—HN—(CH₂)₃Si(OR)₃

e) H₂N—(CH₂)₂—HN—(CH₂)₂—HN—(CH₂)₃Si(OR)₃

f) OCN—(CH₂)₃Si(OR)₃

g) HS—(CH₂)₃Si(OR)₃

h) H₂COCH—CH₂—O13 (CH₂)₃Si(OR)₃

i) H₂C═C(CH₃)—COO—(CH₂)₃Si(OR)₃

j) H₂C═CH—Si(OR)₃.

The aforementioned bifunctional organosilanes can be reacted withorganic polymers in a manner which is schematically represented asfollows:

It is also possible however, firstly to react the inorganic componentsB) and/or C), optionally with the bifunctional organosilanes,essentially with the formation of Si—O—Si bonds, and to effect reactionwith the organic polymer thereafter.

Examples of organic polymers A) include polyimides, polycarbonates,polyesters, polyamides, polyketones, polyethers, polystyrenes,polyacrylonitriles, polyacrylamides, polymethacrylate esters,polyacrylate esters, polyvinyl esters, polyvinyl ethers andpolyolefines, as well as copolymers and mixtures thereof (“blends”).

Commercially available polyol polymers are preferably used, e.g. thosebased on polyesters, polyacrylic esters or polymethacrylic esters, andpolymers which contain isocyanates. Examples thereof include polyolsbased on polyacrylates or linear and branched polyesters orpolyesters/polyethers.

If a plurality of organic polymers A) is used, these can also be reactedwith each other, for example by the addition of polyol polymers topolymers which contain isocyanate groups.

Inorganic particles B) in the sense of the invention are oxides orhydrated oxides of metals, semimetals or non-metals which have a primaryparticle diameter of 1 to 100 nm, preferably 5 to 50 nm. This is a rangewithin which the scattering of visible light (about 400 to 700 nm) isnegligibly low, and highly transparent materials can thus be obtained.Examples of inorganic particles according to the invention includesilica sols (SiO₂), boehmite sols (Al(O)OH) and/or TiO₂ sols. Silicasols in organic solvents are preferred, since they can readily be mixedwith other solvents, e.g. those which contain organic polymer A).However, in order to increase the solids content of the mixtureaccording to the invention it is also possible to disperse inorganicparticles B) in the organic polymer without the use of additionalsolvent (solvents which are necessary for dissolving the organic polymerare not “additional solvents” in the sense of the invention).Dispersions of SiO₂ particles in polar organic polymers, e.g. inpolymers which contain OH groups, are preferably used. Dispersions inpolyols, which are usually reacted with organic polymers which containisocyanates, are most preferably used.

Organic-inorganic binders C) in the sense of the invention arepolyfunctional organosilanes which contain at least 2, preferably atleast 3 silicon atoms which each comprise 1 to 3 alkoxy or hydroxygroups, wherein the silicon atoms are each bonded by at least one Si—Cbond to a structural unit which links the silicon atoms.

Examples of linking structural units in the sense of the inventioninclude linear or branched C₁ to C₁₀ alkylene chains, C₅ to C₁₀cycloalkylene radicals, aromatic radicals e.g. phenyl, naphthyl orbiphenyl, and combinations of aromatic and aliphatic radicals also. Thealiphatic and aromatic radicals may also contain hetero atoms such asSi, N, O, S or F.

Examples of polyfunctional organosilanes include compounds of generalformula (I)

R⁶ _(4−i)Si[(CH₂)_(n)Si(OR⁷)_(a)R⁸ _(3−a)]_(i)  (I)

wherein

i=2 to 4, preferably i=4,

n=10, preferably n=2 to 4, most preferably n=2, and

R⁶=alkyl or aryl,

R⁸=alkyl or aryl, preferably R⁸=methyl,

a=1 to 3,

R⁷=alkyl or aryl, preferably R⁷=methyl, ethyl or isopropyl;

if a=1, R⁷ may also denote hydrogen.

Other examples include cyclic compounds of general formula (II)

wherein

m=3 to 6, preferably m=3or 4,

n=2 to 10, preferably n=2.

R⁸=a C₁-C₆ alkyl or C₆-C₁₄ aryl,

preferably R⁸=methyl or ethyl, most preferably R⁸=methyl,

R¹⁰=an alkyl or aryl, preferably R¹⁰=methyl,

c=1 to 3,

R⁹=an alkyl or aryl, preferably R⁹=methyl, ethyl or isopropyl;

if c=1, R⁹ may also denote hydrogen.

Other examples of polyfunctional organosilanes include compounds ofgeneral formula (III)

Si[(OSiR¹¹)₂(CH₂)_(p)Si(OR¹²)d(R¹³)_(3−d)]  (III)

wherein

p=1 to 10, preferably p=2 to 4, most preferably p=2,

R¹¹=an alkyl or aryl, preferably R¹¹=methyl,

R¹³=an alkyl or aryl, preferably R¹³=methyl,

d=1 to 3,

R¹²=an alkyl or aryl, preferably R¹²=methyl, ethyl or isopropyl;

if d=1, R¹² may also be hydrogen.

Other examples of polyfunctional organosilanes include silanols oralkoxides, e.g.

a) Si[(CH₂)₂Si(OH)(CH₃)₂]₄

b) cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄, or

c) cyclo-{OSiMe[(CH₂)₂Si(OEt)₂Me]}₄,

d) cyclo-{OSiMe[(CH₂)₂Si(OMe)Me₂]}₄,

e) cyclo-{OSiMe[(CH₂)₂Si(OEt)₃]}₄.

The mixtures according to the invention may additionally containalkoxides of metals and nonmetals, e.g. in order to increase theirwear-resistance. Examples thereof include alkoxides of general formula(IV)

R³ _(x−y)M(OR²)_(y)  (IV)

wherein

M=Si, Sn, Ti, Zr (x=4, y=1 to 4), or

M=B, Al (x=3, y=1 to 3),

R², R³=alkyl, aryl,

preferably R², R³=methyl, ethyl, isopropyl, n-butyl, sec-butyl,tert-butyl, phenyl, most preferably R², R³=methyl and ethyl.

Examples include Si(OEt)₄, Si(OMe)₄, H₃C—Si(OEt)₃, C₆H₅—Si(OEt)₃,B(OEt)₃, Al(O′Pr)_(3 or) Zr(O′Pr)₄. Si(OEt)₄ is preferably used. Insteadof monomeric alkoxides, condensation products thereof can also be used.Examples which are commercially available include Si(OEt)₄ condensates.

In addition, the mixtures according to the invention may also containcatalysts for speeding up the reactions of hydrolysis and condensation,or pigments for imparting coloration or for protection from corrosion.

Examples of suitable solvents D) include alcohols such as methanol,ethanol, isopropanol. 1-butanol 2-butanol, 1,2-ethanediol and glycerol,ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone andbutanone, esters such as ethyl acetate or butyl acetate, aromaticcompounds such as toluene or xylene, ethers such as tert.-butyl methylether, and aliphatic hydrocarbons.

Organic and inorganic acids or bases, as well as organometalliccompounds or metal alkoxides, can be used as catalysts.

In order to produce the mixtures according to the invention, thecomponents are mixed in any sequence. The organic polymers arepreferably used in a solvent.

For the production of mixtures which result in materials in which theorganic polymer and the inorganic component are not covalently bonded,the following embodiment is preferred: the organic polymer A) is placedin a vessel in a solvent D), the inorganic particles B), preferably as atransparent dispersion in a solvent, and the organic-inorganic binder C)are added with stirring, optionally followed by alkoxides, othersolvents, water catalysts and/or pigments.

For mixtures from which materials are to be produced in which theorganic polymer and the inorganic component are covalently bonded sothat they are stable towards hydrolysis, in one preferred embodiment theorganic polymer A) is first reacted with a bifunctional organosilane.After this reaction is complete, the inorganic particles B), preferablyas a transparent dispersion in a solvent, and the organic-inorganicbinder C) are added, and finally other solvents, water, catalysts and/orpigments are added.

In a further embodiment, bifunctional organosilanes can also first bereacted with the inorganic particles B) and/or the organic-inorganicbinder C). Thereafter, the organic polymer A) is added, and alkoxides,other solvents, water, catalysts and/or pigments are optionally added.

In the embodiments cited above, the inorganic particles B) can also beused as dispersions in the organic polymer A), optionally in thepresence of solvents.

The mixtures according to the invention are ready to use immediatelyafter mixing the starting components, an can be used for coatings, forexample. However, the mixtures are preferably stirred for a certainlength of time. In the presence of water and condensation catalysts inparticular, condensation polymers are thus formed from theorganic-inorganic binder or from the metal alkoxides which areoptionally added. Mixtures which are treated in this-manner curesignificantly more rapidly than those which are freshly prepared.

Organic-inorganic hybrid materials can be produced by removing thevolatile constituents from the mixtures according to the invention. Thiscan be effected, for example, by evaporating the volatile constituentsat temperatures from −10 to 200° C. preferably 15 to 60° C.

The organic-inorganic hybrid materials which arc thus obtained consistof interpenetrating networks or of a molecular mixture of inorganic andorganic components. The inorganic network is formed from the inorganicparticles B), from the organic-inorganic binder C) and optionally fromalkoxides and/or bifunctional organosilanes or from the correspondinghydrolysis and condensation products of all the aforementionedcomponents. It is a characteristic of the materials that the inorganicnetwork contains structural units in which silicon atoms are linked viaorganic radicals, to which they are bonded via Si—C bonds.

The new materials are suitable for the production of coatings andmouldings, for example. On account of their high content of inorganiccomponents, mouldings produced from the materials according to theinvention exhibit reduced flammability compared with mouldings producedfrom polyurethanes, for example.

Coatings of the materials are distinguished by their good adherence,high transparency, resistance to solvents and chemicals, resistance towear, and flexibility. The coatings cure very well on glass and metals,and also cure well on many organic and ceramic materials. Thus, forexample, primer coats of polyurethane lacquers can be overcoated withoutproblems. Coatings which exhibit good adherence can also be appliedwithout pre-treatment to transparent plastics such as polycarbonates, inorder to improve the scratch-resistance thereof.

The organic-inorganic hybrid materials according to the invention can beused, as transparent coatings for example, for applications where highwear-resistance, flexibility and resistance to chemicals and solvents isrequired. Examples of suitable applications include covering lacquers inthe motor vehicle sector, in the marine sector (ships, harbourinstallations) and in the construction of chemical apparatus (e.g.internal and external coatings for pipelines or reactors).

For use in the automobile sector, a high wear-resistance together with aresistance to solvents and chemicals is essential. In order to avoid thechipping (over a large area) of lacquer films when they are damaged bydeformation, the coatings also have to exhibit a certain flexibility.Coatings can be produced from the organic-inorganic hybrid materialsaccording to the invention which exhibit a resistance to solvents andchemicals which is just as good or sometimes even better than that ofthe best covering lacquers which have been tested in practice. At thesame time, the materials according to the invention exhibit asignificantly improved wear-resistance. The coatings according to theinvention, which have a high content of inorganic components, are alsoparticularly suitable as anti-fouling coatings for ships.

On account of their repellent effect in relation to many colorants, anddue to their good resistance to solvents, the coatings according to theinvention are also particularly suitable as anti-graphiti coatings.Firstly, the coatings are poorly wetted, so that a film of colorantcoalesces to form droplets, and secondly a dried colorant caneffortessly be removed. The coatings can also be applied toalready-existing coatings, in order to provide effective protection forvehicles or buildings.

EXAMPLES

The polyacrylates which were used as organic polymers are commerciallyavailable, under the trade name Desmophen®, from Bayer AG, D-51386Leverkusen. Unless indicated otherwise. Desmophen® A 665 (3.0% of OHgroups) was used as a 65% solution in n-butyl acetate/xylene (3:1), andDesmophen® A 450 (1.0% of OH groups) was used as a 50% solution inn-butyl acetate.

As described in Examples 1 and 2, respectively,cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ (“D4 silanol”) andcyclo-{OSiMe[(CH₂)₂Si(OEt)₂Me])}₄ (“D4 diethoxide”) were produced by thehydrosilylation of cyclo-{OSi(CH₃)(C₂H₃)}₄ with HSiClMe₂ or HSiCl₂Me andsubsequent hydrolysis or alcoholysis.

Si[(CH₂)₂Si(OH)Me₂]₄ (“TVS silanol”) was correspondingly produced fromtetravinylsilane. HSiClMe₂ and subsequent hydrolysis, as described in DEOS 19 603 242.

The hydrosilylation catalysts were commercially available catalysts,e.g. “Silopren U Pt/S catalyst” (a 68% solution in isopropanol of a Ptcomplex which is substituted with cyclo-{OSi(CH₃)(C₂H₃)}₄ ligands)supplied by Bayer AG, D-51368 Leverkusen, or were produced as describedabove.

The aforementioned compounds were synthesised in an argon atmosphere orunder vacuum.

The (organo)silica sol used consisted of a dispersion of about 30% byweight SiO₂ (primary particle diameter about 9 nm) in isopropanol. Thequoted SiO₂ content, which is given with respect to the total solidscontent, results from the amount of (organo)silica sol (SiO₂ content30%) and TEOS (SiO₂ content 28.8% for complete condensation) added.Films were applied to glass by means of a film-drawing frame (doctorblade), and were cured for 1 hour at 110° C. in a recirculating air ovenunless indicated otherwise.

A cross-cut adhesion test according to ISO 2409 was performed in orderto test the hardness. The pencil hardness was determined according toASTM D 3363-92a with pencils of the “Stabilo-micro 8000” brand (Schwan.Germany), with hardnesses from B to 7H. The hardness of the pencil whichis quoted is that which did not scratch the film through to thesubstrate. The pendulum hardness was determined according to DIN 53 157.The Erichsen cupping index was determined according to DIN ISO 1520.

The resistance to solvents was tested visually (time of action: 1 minuteor 5 minutes), and was assessed from “0” (unchanged) to “5” (changedconsiderably, e.g. blister formation, detachment or dissolution, orsoftening).

The washing train test was performed in a laboratory washing trainconsisting of a rotating brush (polyethylene bristles) and two nozzlesfor supplying the abrasive medium (quartz sand, average particle size 25μm). The coated plate to be tested was moved backwards and forwards tentimes under the brush and was sprayed with the water-sand mixture at thesame time. After 10 cycles, the surface was cleaned with ethanol and theloss in gloss was determined (gloss measurement at 20° C.).

The efficacy as an anti-graffiti coating was tested by the action for 1hour of a 1% solution of fuchsine in water-ethanol-butyl glycol (1:1:1).The dry film was wiped with a paper towel saturated with ethanol, andthe remaining dye was classified visually into the categories “slightlypink” and “pink”. When no residual fuchsine was discernible, this wasdenoted as “removed without residue”.

Percentages are given as percentages by weight unless indicatedotherwise.

Example 1

Coating of powdered activated carbon with H₂PtCl₆

49.5 g of Norit CN 1 activated carbon were slurried in 300 ml ofdouble-distilled water and were mixed with 200 ml of an aqueous H₂PtCl₆solution which contained 0.5 g Pt, calculated as the metal. The batchwas subsequently stirred for 10 minutes and the catalyst was filteredoff by suction through a Buchner funnel. The moist, crude product (153g) was dried at 0.1 Pa and 110° C. and was stored under argon. Thecatalyst contained 1% platinum.

Synthesis of cyclo-{OSiMe[(CH₂)₂SiClMe₂]}₄

69 g (726.7 mmol) chlorodimethylsilane and 800 mg of the catalyst(produced as described above) were added to 50 g (145.2 mmol)cyclo-{OSi(CH₃)(C₂H₃)}₄ in 120 ml THF. The reaction mixture was heatedto 50° C., whereupon no generation of heat was observed, even after 2hours at this temperature. After a further 20 hours at 55 to 60° C. thebatch was cooled to room temperature and the catalyst was filtered offthrough a glass frit. The clear, colourless filtrate was freed fromvolatile constituents under vacuum, and the product was obtained as acolourless oil.

Synthesis of cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄

105 g (145.2 mmol) cyclo-{OSiMe[(CH₂)₂SiClMe₂]}₄ in 100 ml diethyl etherwas added drop-wise, over one hour, to a mixture consisting of 87.4 ml(63.6 g; 628.3 mmol) triethylamine. 12.1 ml (12.1 g; 672.2 mmol) waterand 2850 ml tert.-butyl methyl ether. After the addition was complete,the batch was stirred for a further one hour and the precipitate oftriethylammonium hydrochloride was filtered off. The volatileconstituents were then removed under vacuum by means of a rotaryevaporator, and the oily residue was taken up in a little THF and wasfiltered through silica gel. After the repeated removal of all thevolatile constituents under vacuum, the product was obtained as aviscous oil.

Yield: 69.5 g, corresponding to 74% theoretical.

Example 2

Synthesis of cyclo-{OSiMe[(CH₂)₂SiCl₂(CH₃)]}₄

249.5 g (725.5 mmol) cyclo-{OSi(CH₃)(C₂H₃)}₄ were placed in a vessel in250 ml toluene (p.a.), and after adding 50 μl of Silopren U catalyst thebatch was heated to 100° C. 30 ml dimethylchlorosilane were then rapidlyadded, whereupon the temperature immediately rose to 110° C. Drop-wiseaddition then commenced of the remaining amount of 332.3 ml (367.2 g;3.19 mol) dimethylchlorosilane. During the drop-wise addition (about 2hours) the temperature of the reaction mixture rose transiently to about120° C., but fell to 107° C. when the final 30 ml were added. Theyellowish reaction mixture was stirred for a further 2 hours at 110° C.and was then cooled to room temperature. After removing the volatileconstituents by condensation under vacuum, a pale yellowish oil wasobtained.

Yield: 581.0 g, corresponding to 99.6% theoretical.

Synthesis of cyclo-{OSiMe[(CH₂)₂Si(OEt)₂(CH₃)]}₄

581.0 g (722.2 mmol) cyclo-{OSiMe[(CH₂)₂SiCl₂(CH₃)]}₄ (produced asdescribed above) were dissolved in 500 ml ethanol and were addeddrop-wise to 476.0 g (10.33 mol) ethanol (p.a.). After the drop-wiseaddition (about 2 hours), during which the temperature of the reactionmixture rose to about 32° C., the batch was heated under reflux for afurther 2 hours, whereupon gaseous hydrogen chloride was still evolvedbriskly. Finally, the volatile constituents were distilled off, firstlyat normal pressure and secondly under vacuum. A slightly yellowish oilwas obtained.

Example 3

D4 silanol/Desmophen® A 665 without additional solvent

15 g cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ were stirred with 108.4 gDesmophen® A 665 until a homogeneous mixture was obtained. 135.5 mlorganosol, 75 ml TEOS and 12 ml 0.1 N hydrochloric acid were then addedand the homogeneous mixture was stirred for a further 2 hours. Solidscontent: 43%.

After application and curing, a transparent, crack-free film wasobtained which exhibited a slight pattern due to drying.

Wet film thickness Dry film thickness Pencil [μm] [μm] hardnessAnti-graphiti test 240 46 6 H removed without residue

Example 4

D4 silanol/Desmophen® A 665 with a low content of organosol

108.4 g Desmophen® A 665, 68 ml organosol, 75 ml TEOS and 12 ml 0.1 Nhydrochloric acid were added to 150 g of a 10% solution ofcyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ in n-butanol.

After application and curing, a transparent, crack-free film wasobtained.

Wet film thickness Dry film thickness Pencil [μm] [μm] hardnessAnti-graphiti test 120 15 5 H slightly pink

Example 5

D4 silanol/Desmophen® A 665 with a high content of organosol

150 g of a 10% solution of cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ in n-butanol,108.4 g Desmophen® A 665, 135.5 ml organosol. 75 ml TEOS and 12 ml 0.1 Nhydrochloric acid were mixed together and stirred for 2 hours. Ahomogeneous mixture was obtained.

Application was effected by spraying (carrier gas: nitrogen);automobile-specific tests:

Resistance Washing Dry film Pendulum Erichsen Resistance to trainthickness hardness cupping to chemicals test [μm] [swings] test [mm]solvents*⁾ [° C.]**⁾ [%]***⁾ 40 130 3.0-4.5 0 36 82.5 0 36 60.3 1 3622.2 2 36 0 45 *⁾xylene, MPA, ethyl acetate, acetone (time of action: 1minute), petrol (10 minutes). **⁾tree gum, brake fluid, pancreatin(50%), NaOH (1%), sulphuric acid (1%); The temperature given correspondsto the first visible damage. ***⁾Loss of gloss after 10 washes,determined at an angle of incidence of 20° (initial gloss, final gloss,difference). By comparison: loss of gloss of a commercially available2-component polyurethane covering lacquer: 35.2.

Example 6

D4 silanol/Desmophen® A 665 with prior reaction of the inorganiccomponents

150 g of a 10% solution of cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ in n-butanol,68 ml organosol. 75 ml TEOS and 12 ml 0.1 N hydrochloric acid were mixedtogether and stirred for 2 hours. A homogeneous mixture was obtained.

After application and curing, a transparent, crack-free film wasobtained.

Wet film thickness Dry film thickness Pencil [μm] [μm] hardnessAnti-graphiti test 120 15 6 H slightly pink

Example 7

D4 silanol/Desmophen® A 665 (70% solution in n-butyl acetate)

1.5 g cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄ were stirred with 10.08 gDesmophen® A 665 until a homogeneous mixture was obtained. 13.6 mlorganosol, 7.5 ml TEOS and 1.2 ml 0.1 N hydrochloric acid were thenadded and the homogeneous mixture was stirred for a further 2 hours.

After application and curing, a transparent, crack-free film wasobtained.

Wet film thickness Dry film thickness Pencil [μm] [μm] hardnessAnti-graphiti test 240 46 6 H slightly pink

Examples 8-10

D4 diethoxide/Desmophen® A 665

The starting materials were mixed together in the sequence given in theTable and the batch was stirred for 2 hours. Homogeneous mixtures wereobtained.

Component Example 8 Example 9 Example 10 D4 diethoxide [g] 5.25 5.255.25 TEOS [g] 5.02 5.02 5.02 ethanol [ml] 10.0 butanol [ml] 10.0 10.00.1N HCl [g] 1.10 1.10 1.10 (organo)silica sol [ml] 10.0 10.0 15.0Desmophen ® A 665 [g] 1.50 1.50 1.50 solids content [%] 28.8 29.0 29.0SiO₂ content [%] 49.9 49.9 57.1

After application and curing, transparent, crack-free films wereobtained.

Wet film Dry film Example. thickness thickness Pencil Anti-graffiti No.[μm] [μm] hardness test 8 120 13 6 H slightly pink 9 120 12 6 H slightlypink 10 120 14 6 H slightly pink

Examples 11 and 12

D4 diethoxide/Desmophen® A 665 with prior reaction of the inorganiccomponents

The (inorganic) components listed in the Table were mixed together andstirred for 2 hours. The organic polymer (Desmophen® A 665) was thenadded and the batches were stirred until homogeneous mixtures werepresent.

Component Example 11 Example 12 D4 diethoxide [g] 5.25 5.25 TEOS [g]5.02 5.02 ethanol [ml] 10.0 10.0 0.1N HCI[g] 1.10 1.10 (organo)silicasol [ml] 10.0 Desmophen ® A 665 [g] 1.0 1.50 solids content [%] 27.629.0 SiO₂ content [%] 25.9 49.9

After application and curing, transparent, crack-free films wereobtained.

Wet film Dry film Example thickness thickness Pencil No. [μm] [μm]hardness Anti-graffiti test 1 120 20 6 H removed without residue 12 12012 6 H slightly pink

Examples 13 and 14

Reaction of Desmophen® A 665 (70% solution in n-butyl acetate) withOCN-(CH₂)₃-Si(OEt)₃

100 g Desmophen® A 665 were stirred with 0.7 g (Example 13) or 3.5 a(Example 14) OCN-(CH₂)₃-Si(OEt)₃ in each case and the batch wasthereafter annealed in a drying oven for 5 hours at 45° C. A colourlessmixture was obtained, the viscosity of which had not changedperceptibly.

D4 silanol/Desmophen® A 665 (functionalised with OCN-(CH₂)₃-Si(OEt)₃)

The starting materials were mixed together with each other in thesequence given in the Table and were stirred for 2 hours. Homogeneousmixtures were obtained.

Component Example 13 Example 14 D4 silanol [g] 1.50 1.50 butanol [ml]13.5 13.5 Desmophen ® A 665 [g] 10.0 (modified according to a))Desmophen ® A 665 [g] 10.0 (modified according to b)) organosol [g] 13.613.6 TEOS [ml] 7.50 7.50 0.1N HCl [g] 1.20 1.20 solids content [%] 33.032.9 SiO₂ content [%] 41.8 42.0

After application and curing, transparent, crack-free films wereobtained.

Wet film Dry film Example thickness thickness Pencil No. [μm] [μm]hardness Anti-graffiti test 13 240 37 6 H removed without residue 14 24026 6 H removed without residue

Examples 15-17

TVS silanol/Desmophen® A 450 (50% solution in n-butyl acetate/xylene(1:1))

2.0 g Si[(CH₂)₂Si(OH)Me₂]₄, 4.0 ml TEOS, 5.0 ml ethanol and 1.0 ml 0.1 Nhydrochloric acid were mixed together and stirred for 1 hour.Thereafter, 2 g Desmophene® A 450 (Example 15), 1.0 Desmophen® A 450(Example 16) or 0.5 g Desmophen® A 450 (Example 17) were added to 2 mlof this solution and stirred until homogeneous mixtures were obtained.

A polycarbonate sheet and an ABS sheet were each coated (90 μm) with thesolutions obtained in this manner, and the coating was cured for 1 hourat 130° C. or 90° C.

The results of cross-cut adhesion tests were as follows:

Example No. Polycarbonate ABS 15 0/0 0/0 16 0/0 0/0 17 0/3 4/5

Example 18

D4 silanol/Desmophen® A 450

1.5 g cyclo-{OSiMe[(CH₂)₂Si(OH)Me₂]}₄, 10 g methyl ethyl ketone, 10 gDesmophen® A 450, 13.6 ml organosol, 7.5 ml TEOS and 1.2 ml of 0.1 Nhydrochloric acid were mixed together and stirred for 2 hours. Ahomogeneous mixture was obtained.

After application and curing, a transparent, crack-free film wasobtained.

Wet film thickness Dry film thickness Pencil [μm] [μm] hardnessAnti-graphiti test 120 16 7 H removed without residue

Comparative Examples 1a-1g

TEOS, H₃C-Si(OEt)₃ or Ph-Si(OEt)₃/Desmophen® A 665 (no organic-inorganicbinder)

The starting materials were mixed together in the sequence given in theTable and stirred for 2 hours. Homogeneous mixtures were obtained.

A glass plate was coated with each of the solutions which were obtainedin this manner (wet film thickness 240 μm) and the coating was cured for15 minutes at 130° C.

Example 1a 1b 1c 1d 1e 1f 1g Desmophen ® 1.51 1.51 1.51 1.51 1.51 1.511.51 A 665 [g] (organo)silica sol 2.22 2.20 1.81 2.11 1.97 1.80 2.11[ml] TEOS [g] 0.86 0.53 0.94 0.98 0.77 0.95 0.98 H₃C—Si(OEt)₃ [g] 0.270.53 0.94 — — — C₆H₅—Si(OEt)₃ [g] — — — 0.21 0.41 0.41 0.21 n-BuOH [g]1.63 1.72 1.63 1.68 1.82 1.79 0.1N hydrochloric 0.19 0.17 0.24 0.19 0.180.21 0.19 acid [g] dry film thickness 28 32 26 24 27 22 38 [μm] pencilhardness 1H 1H 1H HB HB HB 1H Anti-graffiti test pink pink pink pinkpink slightly pink pink

Comparative Examples 2a and 2b

TEOS. H₃C-Si(OEt)₃ or Ph-Si(OEt)₃/Desmophen® A 665 (no organic-inorganicbinder)

The starting materials were mixed together in the sequence given in theTable and stirred for 2 hours. Homogeneous mixtures were obtained.

A glass plate was coated with each of the solutions which were obtainedin this manner (wet film thickness 240 μm) and the coating was cured for15 minutes at 130° C.

Example 2a 2b Desmophen ® A665 [g] 1.51 1.51 (organo)silica sol [ml]2.11 1.97 TEOS [g] 0.98 0.77 C₆H₅—Si(OEt)₃ [g] 0.21 0.41 2-butanone [g]0.84 0.91 0.1N hydrochloric acid 0.19 0.18 [g] dry film thickness [μm]42 38 pencil hardness 2 H 2 H Anti-graffiti test pink pink

What is claimed is:
 1. A composition comprising A) an organic polymer,B) inorganic particles, C) an inorganic-organic binder comprising anorganosilane having at least two silicon atoms each comprising 1 to 3alkoxy or hydroxy groups, wherein the silicon atoms are each bonded byat least one Si—C bond to a structural unit which links the siliconatoms and D) a solvent.
 2. The composition of claim 4 wherein saidinorganic-organic binder comprises a compound corresponding to theformula

wherein m has a value of 3to6 n has a value of 2 to 10, c has a value of1 to 3, R⁸ represents a C₁-C₆ alkyl or C₆-C₁₄ aryl group, R⁹ representsan alkyl or aryl group, provided that if c has a value of 1, R⁹ mayrepresent hydrogen, and R¹⁰ represents an alkyl or aryl group.
 3. Thecomposition of claim 1 wherein said organic polymer comprises a polyolpolymer.
 4. The composition of claim 2 wherein said organic polymercomprises a polyol polymer.
 5. The composition of claim 1 wherein saidorganic polymer comprises a polymer containing a group which formsSi—O—Si bonds.
 6. The composition of claim 2 wherein said organicpolymer comprises a polymer containing a group which forms Si—O—Sibonds.
 7. The composition of claim 1 wherein said inorganic particlescomprise an oxide or a hydrated oxide of a metal, semimetal or non-metalhaving a primary particle diameter of 1 to 100 nm.
 8. The composition ofclaim 2 wherein said inorganic particles comprise an oxide or a hydratedoxide of a metal, semimetal or non-metal having a primary particlediameter of 1 to 100 nm.
 9. The composition of claim 3 wherein saidinorganic particles comprise an oxide or a hydrated oxide of a metal,semimetal or non-metal having a primary particle diameter of 1 to 100nm.
 10. The composition of claim 4 wherein said inorganic particlescomprise an oxide or a hydrated oxide of a metal, semimetal or non-metalhaving a primary particle diameter of 1 to 100 nm.
 11. The compositionof claim 5 wherein said inorganic particles comprise an oxide or ahydrated oxide of a metal, semimetal or non-metal having a primaryparticle diameter of 1 to 100 nm.
 12. The composition of claim 6 whereinsaid inorganic particles comprise an oxide or a hydrated oxide of ametal, semimetal or non-metal having a primary particle diameter of 1 to100 nm.
 13. The composition of claim 1 wherein said inorganic particlescomprise an oxide or a hydrated oxide of silica having a primaryparticle diameter of 1 to 100 nm.
 14. The composition of claim 2 whereinsaid inorganic particles comprise an oxide or a hydrated oxide of silicahaving a primary particle diameter of 1 to 100 nm.
 15. The compositionof claim 3 wherein said inorganic particles comprise an oxide or ahydrated oxide of silica having a primary particle diameter of 1 to 100nm.
 16. The composition of claim 4 wherein said inorganic particlescomprise an oxide or a hydrated oxide of silica having a primaryparticle diameter of 1 to 100 nm.
 17. The composition of claim 5 whereinsaid inorganic particles comprise an oxide or a hydrated oxide of silicahaving a primary particle diameter of 1 to 100 nm.
 18. The compositionof claim 6 wherein said inorganic particles comprise an oxide or ahydrated oxide of silica having a primary particle diameter of 1 to 100nm.
 19. A molding or coating prepared from the composition of claim 1.